I have a big bag of 60mm collagen casings, had to buy in bags of 25 and cost about $20. There is no way I will use them all so, if anyone wants some casings I am willing to share some. Send me a PM if you are interested. Oh I should add, the directions state they are to be "soaked or flushed for 20-30 minutes in warm water (26°C) with 10-15% salt concentration. This will improve the elasticity and ‘machinability’ of the casings." And they are edible substitutes for natural beef middles.